Spark-plug.



W. L. HILL.

SPARK PLUG.

APPLICATION FILED we; I. 19".

1,270,521. Patented June 25,1918.

1 FIG. 2

[N VENTOR.

A TTORNE Y.

wfiumcm;

UNITED STATES PATENT OFFICE.

WALTER L. BILL. OF WICHITA, KANSAS.

SPARK-PLUG.

Application flied August 7. 1917.

To all whom it may concern:

Be it known that I. WALTER L. HILL, a citizen of the United States.residing at 'ichita. in the county of Sedgwick and State of Kansas, haveinvented certain new and useful Improvements in Spark-Plugs, of whichthe following is a description. referring to the accompanying drawings,which form a part of this specification.

The objects of the invention are namely. to provide a plurality ofcontact points for ignition purposes. to cause the electric current tomake two jumps and intensify to the extent that the carbon will beconsumed and also to increase the flame: to provide a central micainsulation rigidly positioned within the spark plug shell and yet besusceptible of easy repairs.

Similar numerals of reference indicate corresponding parts in all thefigures of the drawings.

In the drawings. Figure 1 is an elevation of my spark plug with portionsremoved for convenience of description. Fig. 2 is a top view of Fig. 1.Fig. 3 is a bottom view of Fig. 1 showing a plurality of contact "pointsstationed around the insulated electriade. Fig. 1 is a modification ofthe view as seen in Fig. 3 and in which only two con tact points areprovided.

Referring to the drawings at 1 is shown a m ca insulation composed of aplurality of mica washers of varying diameters to conform to the shapeas disclosed. At 2 is shown the IHQ'LnlllC shell of the spark plug whichis provided with a hexagon nut and threads as in common practice. Passedupwardly through the bore of the mica insulation 1 is an electrode 3provided with screw threads at the upper portion thereof and upon whichis threaded the nut grooyed at 5 to receive the contact terminal. The lqqwer portion of 3 is provided with a shoulder or head G which contactsthe base of the mica insulation 1. and by means of 1 washers will restupon the base 3 of the.v

The insulation 1 is also shouldered at it and the flange 10 of the shell2 as shown.

Specification of letters Patent.

Patented June 25, 1918.

Serial N'o. 184.877.

in the dotted line position is now tightly crimped down upon 9 to assumethe position 11. This makes the insulation 1 and shell '2 an integralunit. but should the lowerend of the mica insulation become damaged. bythe removal of the electrode 3 the damaged portions may be replaced ,andthe electrode then returned to position; To the lower end of 1 isrigidly attached a band 12 provided with a plurality of vertical contactbars 13 attached thereto as at 11. the lower end of each contact bar 13being bent inwardly toward the electrode 3 but separated therefrom by agap 15. The upper end of each contact bar is also separated from thebase of the shell 2 by a gap 16. The object of this device being to acta conductor between the shell 2 and the electrode 3 and to cause theelectric current to jump the gap at 15 and likewise at 16. The ap at 16is preferably made greater than t 1e gap at 15. the object being toinsure a spark thatwill give perfect ignltion at all speeds of theengine. At low speed ignition will prove more perfeet at 15 due to ashorter spark but of suflicie'nt duration. while at high speeds thespark obtained at 16 will be of greater volume than at 15 which willcompensate for the shorter duration due to high speed of the engine.Such other modifications may be employed as lie within the scope of theappended claims.

Having fully described my invention. I claim the following as new andpatentable:

1. A spark plug comprising a threaded shell provided with a lowerflanged portion and a central mica insulation extending through saidshell and a shoulder on said insulation supported by said lower flangedshell portion. and an upper flange on said shell adapted to be tightlycrimped upon said insulation as specified: aid insulation comprising aplurality of mica wa hers of varying diameters. an electrode passedthrough said washers. said electrode having a shoulder near the lowerend thereof and below which extends a portion of said electrode and athreaded upper end portion of aid electrode and a nut screwed thereuponand adapted to coact with said shoulder portion to solidly compact themica washers therebetween into an integral insulation; and a bandrigidly attached to the lower portion of said insulation and a pluralityof vertical bars attached to said band. the upper end of each bar beingseparated from the base of the plug by a gap and the lower provided wit1 a lower flanged 'iortion and a p through said shell and a shoulderqltsai'd IIISHlahIOH central mica insulation extenging supported by saidlower/ flanged shell "or tion, and an upper flangeonsaid sell adapted tobe tightlv crim ed '11 on said insulation as specified; sai insu etioncorn; prising a plurality of mica washers of varying 1 said washers,said electrode having a shoulder near the lower end thereof and belowwhich extends a portion of said electrode and a threaded upper endportion of said ameters, an electrode passed through electrode and a nutscrewed thereupon and adapted to roact witlrsaid shoulder portion tosolidlyrompaet the mica washers therebetn'een into an integralinsulation; and a band rigidly attached to the'lower portion of saidinsu ation and a plurality of vertical bars attached to said band, theup er end of each bar being separatedfrom t e base of the plug by a gapand the lower end of said contact bar 'curving inwardly toward butseparated by a gap from the protruding end of said electrode, the gap atthe electrode being less than the gap at the base of the plug for thepur oses as specified.

ALTER L. HILL. Witnesses: v

CLAUDE C. STANLEY, U. G. CHARLES.

